Clean up and export cancel_dirty_page() to modules
Make cancel_dirty_page() act more like all the other dirty and writeback
accounting functions: test for "mapping" being NULL, and do the
NR_FILE_DIRY accounting purely based on mapping_cap_account_dirty()).
Also, add it to the exports, so that modular filesystems can use it.
Acked-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/truncate.c b/mm/truncate.c
index 4a38dd1..ecdfdcc 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -60,12 +60,16 @@
WARN_ON(++warncount < 5);
}
- if (TestClearPageDirty(page) && account_size &&
- mapping_cap_account_dirty(page->mapping)) {
- dec_zone_page_state(page, NR_FILE_DIRTY);
- task_io_account_cancelled_write(account_size);
+ if (TestClearPageDirty(page)) {
+ struct address_space *mapping = page->mapping;
+ if (mapping && mapping_cap_account_dirty(mapping)) {
+ dec_zone_page_state(page, NR_FILE_DIRTY);
+ if (account_size)
+ task_io_account_cancelled_write(account_size);
+ }
}
}
+EXPORT_SYMBOL(cancel_dirty_page);
/*
* If truncate cannot remove the fs-private metadata from the page, the page